Note 6. Railcar Leasing and Management Services Group Proceeds from Sale of Railcars (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019		Dec. 31, 2018
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		$ 1,999.4		$ 3,005.1		$ 2,509.1
Operating profit on sales of leased railcars:		(124.5)		416.3		315.1
Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		802.3		1,117.2		842.8
Operating profit on sales of leased railcars:		353.7		406.6		351.1
Sales of Leased Railcars [Domain] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		193.1		566.4		344.4
Operating profit on sales of leased railcars:		$ 17.7		$ 91.9		$ 71.9
Operating profit margin on sales of leased railcars:		9.20%		16.20%		20.90%
Railcar Owned Greater than One Year [Member] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		$ 138.7		$ 205.7		$ 230.5
Operating profit on sales of leased railcars:		$ 17.3		$ 50.5		$ 50.4
Operating profit margin on sales of leased railcars:		12.50%		24.60%		21.90%
Railcar Owned One Year or Less [Member] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		$ 54.4	[1]	$ 360.7	[2]	$ 113.9
Operating profit on sales of leased railcars:		$ 0.4		$ 41.4		$ 21.5
Operating profit margin on sales of leased railcars:		0.70%		11.50%		18.90%
Operating Segments [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating profit on sales of leased railcars:		$ 418.2		$ 704.1		$ 558.9
Operating Segments [Member] | Railcar Leasing and Management Services Group [Member]
Property Subject to or Available for Operating Lease [Line Items]
Sales of leased railcars:		802.3		1,117.2		842.8
Operating profit on sales of leased railcars:	[3]	$ 353.7		$ 406.6		$ 351.1
Operating profit margin on sales of leased railcars:		44.10%		36.40%		41.70%

[1] Beginning in the fourth quarter of 2020, we made a prospective change in the presentation of sales of railcars from the lease fleet. See Note 1 for more information.

[2] Includes revenues associated with sales-type leases of $160.5 million for the year ended December 31, 2019.

[3] Operating profit includes: depreciation; maintenance and compliance; rent; and selling, engineering, and administrative expenses. Amortization of deferred profit on railcars sold from the Rail Products Group to the Leasing Group is included in the operating profits of the Leasing Group, resulting in the recognition of depreciation expense based on our original manufacturing cost of the railcars. Interest expense is not a component of operating profit and includes the effect of hedges.